A QuerySnapshot contains zero or more [QueryDocumentSnapshot] QueryDocumentSnapshot objects representing the results of a query. The documents can be accessed as an array via the [documents] property or enumerated using the [forEach] method. The number of documents can be determined via the [empty] and [size] properties.
QuerySnapshot
Package
@google-cloud/firestoreConstructors
(constructor)(_query, _readTime, _size, docs, changes)
constructor
(
_query
:
Query<T>
,
_readTime
:
Timestamp
,
_size
:
number
,
docs
:
()
=
>
Array<QueryDocumentSnapshot<T>
> ,
changes
:
()
=
>
Array<DocumentChange<T>
> );
Constructs a new instance of the QuerySnapshot
class
| Name | Description |
| _query | Query
<T>
The originating query. |
| _readTime | Timestamp
The time when this query snapshot was obtained. |
| _size | number
The number of documents in the result set. |
| docs | () => Array
< QueryDocumentSnapshot
<T>>
A callback returning a sorted array of documents matching this query |
| changes | () => Array
< DocumentChange
<T>>
A callback returning a sorted array of document change events for this snapshot. |
Properties
docs
get
docs
()
:
Array<QueryDocumentSnapshot<T>
> ;
An array of all the documents in this QuerySnapshot.
{Array.
| Type | Description |
|---|---|
| Array < QueryDocumentSnapshot <T>> |
let query = firestore.collection('col').where('foo', '==', 'bar');
query.get().then(querySnapshot => { let docs = querySnapshot.docs; for (let doc of docs) { console.log( Document found at path: ${doc.ref.path}
); } });
empty
get
empty
()
:
boolean
;
True if there are no documents in the QuerySnapshot.
{boolean} QuerySnapshot#empty
| Type | Description |
|---|---|
| boolean |
let query = firestore.collection('col').where('foo', '==', 'bar');
query.get().then(querySnapshot => { if (querySnapshot.empty) { console.log('No documents found.'); } });
query
get
query
()
:
Query<T>
;
The query on which you called get() or onSnapshot() in order to get this QuerySnapshot.
{Query} QuerySnapshot#query
| Type | Description |
|---|---|
| Query <T> |
let query = firestore.collection('col').where('foo', '==', 'bar');
query.limit(10).get().then(querySnapshot => { console.log( Returned first batch of results
); let query = querySnapshot.query; return query.offset(10).get(); }).then(() => { console.log( Returned second batch of results
); });
readTime
get
readTime
()
:
Timestamp
;
The time this query snapshot was obtained.
{Timestamp} QuerySnapshot#readTime
| Type | Description |
|---|---|
| Timestamp |
let query = firestore.collection('col').where('foo', '==', 'bar');
query.get().then((querySnapshot) => { let readTime = querySnapshot.readTime; console.log( Query results returned at '${readTime.toDate()}'
); });
size
get
size
()
:
number
;
The number of documents in the QuerySnapshot.
{number} QuerySnapshot#size
| Type | Description |
|---|---|
| number |
let query = firestore.collection('col').where('foo', '==', 'bar');
query.get().then(querySnapshot => { console.log( Found ${querySnapshot.size} documents.
); });
Methods
docChanges()
docChanges
()
:
Array<DocumentChange<T>
> ;
Returns an array of the documents changes since the last snapshot. If this is the first snapshot, all documents will be in the list as added changes.
{Array.
| Type | Description |
|---|---|
| Array < DocumentChange <T>> |
let query = firestore.collection('col').where('foo', '==', 'bar');
query.onSnapshot(querySnapshot => { let changes = querySnapshot.docChanges(); for (let change of changes) { console.log( A document was ${change.type}.
); } });
forEach(callback, thisArg)
forEach
(
callback
:
(
result
:
firestore
.
QueryDocumentSnapshot<T>
)
=
>
void
,
thisArg
?:
unknown
)
:
void
;
Enumerates all of the documents in the QuerySnapshot. This is a convenience method for running the same callback on each QueryDocumentSnapshot that is returned.
| Name | Description |
| callback | (result: FirebaseFirestore.QueryDocumentSnapshot
<T>) => void
A callback to be called with a [QueryDocumentSnapshot] QueryDocumentSnapshot for each document in the snapshot. |
| thisArg | unknown
The |
| Type | Description |
|---|---|
| void |
let query = firestore.collection('col').where('foo', '==', 'bar');
query.get().then(querySnapshot => { querySnapshot.forEach(documentSnapshot => { console.log( Document found at path: ${documentSnapshot.ref.path}
); }); });
isEqual(other)
isEqual
(
other
:
firestore
.
QuerySnapshot<T>
)
:
boolean
;
Returns true if the document data in this QuerySnapshot
is equal to the provided value.
| Name | Description |
| other | FirebaseFirestore.QuerySnapshot
<T>
The value to compare against. {boolean} true if this |
| Type | Description |
|---|---|
| boolean |
